How long can I run the 3.73 gearing? 8.5x17 Wheels wrapped with BF Goodrich 39x13.50r17 km3s..

[Deleted member 30519]

I ran 38" Patagonias on 3.73 gears for about 6 months with my M/T before upgrading to 5.13 gears.

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[Wheelin98TJ]

Yes, other people are doing it, but mainly with 35's or 37's. 39's is a lot of sidewall to put on a width that small.

More sidewall helps.

 

[RLOW]

So nobody is gonna say anything anything about running a 39x13.50 tire on a 8.5" wide wheel? I'm surprised a tire shop would even mount that.

8.5 Is the minimum recommended width for this tire..

 

[Uparms]

6 speed, manual, as long as you like.

 

[Aonarch]

I think I would prefer

33 = 4.56
35 = 4.88
37+ = 5.13

At 4.10 and 33s, 5th and 6th feel really tall to me.

I edited my post with that in mind. Typically you can go one gear size smaller or higher than what I posted.

There is a nifty table that I posted a week ago or so if anyone is interested. It shows the speeds and rpms for all of the combos.

For me, I have C rated 35s on lightweight wheels, with the Livernois tune. 4.10s are fine for me, but I'd prefer 4.56s. However I'll only ever regear if I go 37s and then I'd go for 4.88s.

 

[BLK HOLE]

Mall Crawler yes, with premature wear included.

No. Just wrong.

 

[Aonarch]

No. Just wrong.

They both agree a 37 is the max for a Dana 44, and even then you need to have a gentle driving style.

I can link dozens of articles and forum threads saying a 35 is the largest tire, or you can look it up yourself.

That fact that you think it's ok to run a 39x13.50 and will have no negative impacts to the drive line over the stock tire size makes me laugh out loud. This isn't worth arguing about so this will be my last post addressing your disagreement.

Back to the video, one thing they address is weight. Harry was talking about his TJ being 3400 pounds. Well a Gladiator Rubicon is 5000 pounds or so, not including gear, so that is going to play a role as well. Even though Harry is talking about his TJ, the video is about Dana 44s generically. They address the differences over the years and call out specific configurations.

 

[Wheelin98TJ]

They both agree a 37 is the max for a Dana 44, and even then you need to have a gentle driving style.

I can link dozens of articles and forum threads saying a 35 is the largest tire, or you can look it up yourself.

That fact that you think it's ok to run a 39x13.50 and will have no negative impacts to the drive line over the stock tire size makes me laugh out loud. This isn't worth arguing about so this will be my last post addressing your disagreement.

Back to the video, one thing they address is weight. Harry was talking about his TJ being 3400 pounds. Well a Gladiator Rubicon is 5000 pounds or so, not including gear, so that is going to play a role as well. Even though Harry is talking about his TJ, the video is about Dana 44s generically. They address the differences over the years and call out specific configurations.

This thread was more focused on "what are the effects of having too high gears".

OP didn't ask about the effects of 39s on a D44.

Harry's TJ is not 3,400 lbs. I see a steel gas tank skid plate. I see steel rock sliders. A stock TJ is more than 3,400 lbs. I had a '98 that was 4,200 lbs and it had less weight added to it than Harry's TJ does.

 

[BLK HOLE]

They both agree a 37 is the max for a Dana 44, and even then you need to have a gentle driving style.

I can link dozens of articles and forum threads saying a 35 is the largest tire, or you can look it up yourself.

That fact that you think it's ok to run a 39x13.50 and will have no negative impacts to the drive line over the stock tire size makes me laugh out loud. This isn't worth arguing about so this will be my last post addressing your disagreement.

Back to the video, one thing they address is weight. Harry was talking about his TJ being 3400 pounds. Well a Gladiator Rubicon is 5000 pounds or so, not including gear, so that is going to play a role as well. Even though Harry is talking about his TJ, the video is about Dana 44s generically. They address the differences over the years and call out specific configurations.

Meanwhile I actually wheel all year long with people doing it and have never seen a failure. I wheel on 39s with my JK and JT (2nd and 3rd gen D44s)....and while I opted to upgrade the JK housing to a Pro Rock (stock one was fine to that point, I just opted to do it)...I STILL have the stock 2nd gen D44s guts (stock axle shafts). In 11yrs they still haven't broken. Both Jeeps have 5.13s. But cool video link, I guess.

Hold your breath...I'll check back in the thread if I prove myself wrong, lol. I'll be out on the rocks Friday...I'm sure everything will fail.

 

[Rahkmalla]

um..for the life of your Jeep. The only one who cares would be you. It is in no way shape or form, bad for your Jeep.

39s are heavy, and 3.73s are not a particularly strong gearset. It is unlikely to damage anything other than the differentials themselves, but to say undergearing will cause NO damage to your jeep is false. It just shouldn't cause any damage to the rest of your jeep.

 

[Wheelin98TJ]

39s are heavy, and 3.73s are not a particularly strong gearset. It is unlikely to damage anything other than the differentials themselves, but to say undergearing will cause NO damage to your jeep is false. It just shouldn't cause any damage to the rest of your jeep.

3.73 not a particularly strong gear set? Can you explain more?

Unlikely to damage anything other than the differentials themselves? Can you explain more on this too?

Being geared too high can cause problems outside the diffs. Clutch wear in a stick and heat in an auto.

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